Unidirectionally cold stretched nonwoven webs of multipolymer fibers for stretch fabrics and disposable absorbent articles containing them

ABSTRACT

A nonwoven web of multipolymer fibers is described that is unidirectionally stretched and permanently elongated at ambient conditions and exhibits a substantial increase in tensile strength in the stretch direction. The ratio of tensile strength of the web in the direction of fiber orientation to the tensile strength in the other direction is at least about 10:1. The ratio of elongation at peak load in a direction transverse to the direction of fiber orientation is at least about 6:1. The multipolymer fibers normally are a blend of polyethylene and a polypropylene homopolymer or copolymer, one of which is a dominant phase and one of which is a dispersed phase. A third component having elastomeric properties that is at least partially miscible with one or both of the other components is included in some blends. The nonwoven webs are stretchable well beyond their initial dimensions in the direction perpendicular to the stretch direction and are especially useful in laminates with elastomeric members for use in disposable absorbent articles to impart elasticity thereto.

FIELD OF THE INVENTION

[0001] The invention relates to elasticized composite fabrics for use indisposable absorbent articles and to the components of these fabrics.

BACKGROUND OF THE INVENTION

[0002] Disposable diapers are composite absorbent articles that aredesigned to be worn about the lower torso as undergarments byincontinent persons and by infants and young children prior to toilettraining. Disposable diapers typically include a liquid impervious backsheet as the outer surface of the diaper, a liquid pervious topsheet asthe inner surface of the diaper for placing adjacent the skin of thewearer, and an absorbent core placed between the topsheet and the backsheet for absorbing urine and other liquids The absorbent core isnormally contained in a central, longitudinally extending region of thediaper and the topsheet and back sheet are normally bonded about theperiphery of the diaper.

[0003] The diaper is placed between the legs with the topsheet next tothe skin and the ends are fastened at the waist to hold the diaper inplace for the collection and retention of urine and feces. One area ofconcern in the development and construction of the modern disposablediaper has been maintaining the wearer's comfort and the fit of thediaper throughout the period of use of the diaper, especially on activeinfants and young children.

[0004] Disposable diapers have front and back waist regions that areusually characterized by side panels or ear flaps that extend in thelateral direction on each end of the diaper so as to encircle the waistand hold the diaper in place. The front waist region normally includes alanding member upon which decorative indicia may be placed. The backwaist region normally includes a securing tab on each side for attachingto the landing member. The securing tab and landing member can beattached by hook and prong fastening means similar to Velcro, by apressure-sensitive adhesive on a securing tab tape, or by other suitablemeans.

[0005] Disposable diapers may also include elasticized waist bands, legcuffs and side panels. The elasticized components improve the fit of thediaper and can assist in precluding leakage from the diaper.

[0006] U.S. Pat. No. 5,242,436 is directed to a disposable diaper thathas an elasticized waist band with a dual tensioning fastening system toimprove the dynamic fit of the elasticized waist band and thecontainment characteristics of the absorbent article. A pair ofelasticized side panels that are elastically extensible in the lateraldirection are disposed in the back waist region between the topsheet andthe back sheet in the ear flaps of the diaper on either side of theabsorbent core.

[0007] The topsheet and the backsheet are extensible, but inelastic. Thewebs can be stretched, but are permanently elongated and do not havesignificant recovery of their prestretched dimension. It is necessary toactivate the topsheet and back sheet in the region of the elastic sidepanels so that the topsheet and back sheet can stretch and recover withthe side panels. The topsheet and back sheet are activated byincremental mechanical stretching in the cross-machine direction. Alaminate of the topsheet, back sheet, and elastic side panel is passedin an untensioned condition through at least one set of meshingcorrugated rolls. The laminate is rendered elastically extensible in thecross direction up to the limit of incremental stretching.

[0008] U.S. Pat. Nos. 4,981,747 and 5,114,781 are directed to thepreparation of composite elastic laminates for use in disposableabsorbent articles, including diapers. The laminates are of elasticmaterials and extendable but nonelastic nonwoven webs. The webs aredescribed as “reversibly necked,” which is to say that the webs arepermanently elongated in one direction and necked down in a directiongenerally perpendicular to the direction of elongation of the web. Theweb is heat treated while necked. The heat treatment is said to impartmemory to the nonelastic webs so that the webs can then be stretched andrecover in a direction generally parallel to the direction of neckdownand perpendicular to the direction of elongation. Extension of thereversibly necked material is described as limited to the pre-neckeddimensions.

[0009] A composite elastic laminate can be prepared by laminating thereversibly necked material to an elastic material. The laminate is saidto be elastic in a direction generally parallel to the direction ofneckdown of the reversibly necked material. A laminate that is elasticin two directions can be prepared if the reversibly necked material islaminated to an elastic material elongated in the direction of extensionof the web and then relaxed. The reversibly necked material is gatheredbetween points of attachment to the elastic material and is said to havestretch and recovery to the extent the gathers allow the elasticmaterial to elongate.

[0010] Hassenboehler, Jr. et al. U.S. Pat. No. 5,244,482 describesanother method for drawing a web of nonelastic nonwoven fibers in themachine direction. The stretched web is said to be useful as a filtermaterial and to have reduced pore size, improved uniformity in poresize, and high lateral elasticity characteristic of stretch fabrichaving approximately 120% elongation to break. The web is said to beuseful in preparing laminates with webs of elastomeric polymers, amongothers.

[0011] The precursor web has substantial bonding and relatively lowprocessing extensibility and is heated to its softening temperature anddrawn in the machine direction. Elastomeric polymer webs and webs having50% standardized elongation before break are said to be totallyunsatisfactory for use in the practice of method.

[0012] It would be desirable to provide alternative composite elasticlaminates that have improved properties, are more versatile, or requireless effort to prepare. It would be desirable to develop nonwoven websfor composite elastic laminates that are strong enough to withstand therigors of incremental mechanical stretching in diaper construction whereit is desirable to use elastomeric strands or scrim for breathability,rather than films.

SUMMARY OF THE INVENTION

[0013] The invention provides a nonwoven web of multipolymer fibers, amethod for making the web, a composite elastic laminate that includesthe web and an elastic component, and a disposable absorbent articlethat includes the composite elastic laminate of the invention. Thelaminate is suitable for use in disposable absorbent articles, includinguse as elasticized side panels in diapers that are subjected toincremental mechanical stretching to activate the topsheet and the backsheet. The laminate is also suitable for use as a discrete stretchablemember that is attached to the side edges of the main body of a garment,including a diaper, and has exceptional cloth like hand.

[0014] The nonwoven web is made from multipolymer fibers that aresubstantially oriented in one direction. A plurality of discrete bondsites throughout the web bond the fibers together. The ratio of thetensile strength of the web in the direction of orientation of thefibers to the tensile strength of the web in the other direction is atleast about 10:1.

[0015] The multipolymer fibers are highly elongatable. The web can bestretched to orient the fibers in one or the other of the machinedirection or the cross machine direction to substantially increase theelongation of the web at peak load in a direction perpendicular to theelongation of the web and to also increase the tensile strength in theweb in the direction of elongation. The web can be stretched in theabsence of heat treatment, which is to say that the web can be stretchedat a temperature from about 35 to 150 degrees Fahrenheit. Normally, theweb will be stretched at an ambient temperature from about 65 to 110degrees Fahrenheit.

[0016] Prior to stretching, the web will typically have an elongation atpeak load in at least one of the machine direction or the cross machinedirection of at least 70 percent. Mechanical stretching permanentlyelongates the web and develops a high degree of stretchability in thedirection perpendicular to the elongation of the web. The elongation atpeak load in the direction perpendicular to the direction of stretch isincreased by a factor of at least about 2:1, and in a more specificaspect of the invention, by a factor of more than 4:1. Composite elasticfabrics made with the nonwoven web of the invention can typically bestretched to the elastic limit of the elastic component since the web isusually capable of stretching farther. The web is substantiallystrengthened and does not undergo thinning and damage during incrementalmechanical stretching.

[0017] The multipolymer fibers can be formed with the different polymersin discrete structural domains or from a blend of polymers that aremiscible, immiscible, or a blend of miscible and immiscible polymers. Ablend can also be used as one component in a multipolymer fiber formedof discrete structural domains. In one embodiment, the polymers areimmiscible and are blended to form a dominant continuous phase and atleast one dispersed phase. Exemplary immiscible polymers includepolyethylene, including linear low density polyethylene andpolypropylene. These polymers are normally considered to be inelastic.Either polymer can be the dominant continuous phase. The blend can alsoinclude an elastic component. The preferred blend includes a thirdcomponent that is at least partially miscible with the two phases andgives the blend highly elongatable characteristics.

[0018] An example of a suitable blend for forming multipolymer fibersis:

[0019] isotactic polypropylene present in an amount of about 65 to 80percent by weight based upon the weight of the blend;

[0020] linear low density polyethylene present in an amount from about 1to 5 percent by weight based upon the weight of the blend; and

[0021] a block or grafted polyolefin copolymer or terpolymer having atleast a portion of the chain thereof miscible with the isotacticpolypropylene and wherein the block or grafted polyolefin copolymer orterpolymer is present in an amount from about 15 to 30 percent by weightbased upon the weight of the blend.

[0022] Examples of such a block or grafted polyolefin copolymer are thecommercially available Catalloy™ copolymers available from Montell.

[0023] The multipolymer fibers can be spunbond continuous filaments,carded discontinuous staple fibers and meltblown fibers. Normally, theweb will be prepared from continuous spunbond filaments.

[0024] In another embodiment, the invention comprises a composite fabricthat has at least one layer of an elastomeric component bonded to atleast one layer of the nonwoven web described above. The elastomericcomponent can be selected from elastic strands, scrim, elastic films,and breathable elastic films. The fabric can be gathered in thedirection in which the nonwoven web component previously was permanentlyelongated by mounting the web to the stretched elastic component andthen relaxing the elastic component in the manner taught in U.S. Pat.No. 5,114,781.

[0025] In yet another embodiment, the invention comprises a method forsubstantially increasing the elongation at peak load of a bondednonwoven web wherein a web of multipolymer fibers is prepared and thenstretched in one of the machine or cross machine directions at atemperature from about 35 to 150 degrees Fahrenheit to permanentlyelongate the web. The elongation at peak load of the web in thedirection perpendicular to the stretch direction is substantiallyincreased. The method can include the additional step, if desired, ofstabilizing the web against retraction of the fibers by lightly bondingthe stretched web, normally through the application of heat andpressure.

[0026] Thus, the invention provides a composite elastic fabric withcloth like hand and good cover characteristics that is suitable for usein disposable absorbent articles, especially as elastic side panels indiapers, either as discrete members attached to the main body of thegarment or in laminates mounted between the topsheet and back sheet. Thenonwoven web component of the composite fabric has the strength toperform well in incremental stretching. The web can be permanentlyelongated in one direction to impart substantial ability to stretch in adirection perpendicular to the direction of elongation, all in theabsence of heat treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Some of the objects and advantages of the invention have beenstated. Others will appear when taken in connection with theaccompanying drawings and photomicrographs, in which:

[0028]FIG. 1 is a perspective view of a portion of a bonded nonwoven webof multipolymer fibers prior to stretching in accordance with theinvention;

[0029]FIG. 2 is a perspective view of the nonwoven web of FIG. 1 afterthe nonwoven web has been permanently elongated in accordance with theinvention and stabilized by application of light bonding;

[0030]FIG. 3 is a schematic of an exemplary process for permanentlyelongating in the machine direction a bonded nonwoven web ofmultipolymer fibers;

[0031]FIG. 4 is a partially broken away top perspective view of aportion of the schematic of FIG. 3 taken along line 4-4 and showing thereduction in the cross direction of the width of the web as the web isstretched;

[0032]FIG. 5 is an exploded perspective view of a laminate of twononwoven webs of the invention as shown in FIG. 2 with elastomericstrands placed between the two webs;

[0033]FIG. 6 is a plan view of the relevant structure of a disposablediaper of the invention having the outer surface back sheet facing theviewer;

[0034]FIG. 7 is an exploded perspective view of a broken away portion ofthe diaper of FIG. 6, showing the placement within the diaper of acomposite fabric of the invention;

[0035]FIG. 8 is a photomicrograph at 5× magnification of a pointbondedspunbond nonwoven web of multipolymer continuous filaments prior tostretching in accordance with the invention;

[0036]FIG. 9 is a photomicrograph showing the web of FIG. 8 at 20×magnification;

[0037]FIG. 10 is a photomicrograph at 5× magnification showing a pointbonded spunbond nonwoven web of multipolymer continuous filaments afterstretching in the machine direction followed by light bonding tostabilize the stretched web against retraction;

[0038]FIG. 11 is a photomicrograph showing the web of FIG. 10 at 20×magnification;

[0039]FIG. 12 is a photomicrograph at 20× magnification of a sectionthrough a pointbonded spunbond nonwoven web of multipolymer continuousfilaments prior to stretching in accordance with the invention andshowing a pointbond horizontally oriented in the body of the fabric; and

[0040]FIG. 13 is a photomicrograph at 20× magnification of a sectionthrough a pointbonded spunbond nonwoven web of multipolymer continuousfilaments after the web has been stretched in accordance with theinvention and showing a pointbond that has become vertically orientatedin the fabric as a result of the stretching.

DETAILED DESCRIPTION OF THE INVENTION

[0041] The invention will be described with particular reference to thedrawings, in which illustrative embodiments of the invention are setforth. It should be understood that persons skilled in the art to whichthis invention pertains may modify the specific details described whilestill continuing to use the invention. The description should beunderstood as a broad teaching of the invention that is directed to thepersons of skill in the applicable arts.

[0042]FIG. 1 is a perspective view of a portion of a bonded nonwoven web20 prepared from multipolymer fibers. The nonwoven fibrous webrepresented in FIG. 1 should be considered in a generic sense to includegenerally planar structures that are relatively flat, flexible andporous and are comprised of multipolymer staple fibers or continuousfilaments. The nonwovens may be carded, spunbonded, wet laid, air laidor meltblown. Normally, prior to stretching, the web will have anelongation at peak load in at least one of the machine direction or thecross machine direction of at least 70 percent. In the embodimentillustrated, the nonwoven fibrous web is a spunbonded nonwovencomprising multipolymer spunbond continuous filaments. The filaments arebonded together at discrete bond sites 22 distributed throughout thefabric to form a unitary, coherent nonwoven web.

[0043]FIG. 8 is a photomicrograph at 5× magnification showing a pointbonded nonwoven fabric of spunbond continuous multipolymer filaments.This same web is shown in FIG. 9 at a magnification of 20 times. Theindividual filaments and the consolidated areas of the point bonds areevident. As is evident from the photomicrographs, the point bonds areplanar and lie in the plane of the web. The point bond sites 22 comprisediscrete areas where the filaments have been fusion bonded by theapplication of heat and pressure. In the embodiment illustrated, thebond sites 22 are point bonds, but other known configurations or shapescould be employed, including lines or other patterns.

[0044] The multipolymer fibers of the invention are predominantly formedfrom polymers that normally are considered nonelastic. Useful polymercombinations for use in the practice of the invention are taught inpublished PCT International Patent Application PCT/US95/15257, filedNov. 22, 1995, and entitled Extensible Composite Nonwoven Fabrics. Thecontents of this application and the teachings contained therein arehereby incorporated by reference in their entirety.

[0045] The term “multipolymer fibers” includes staple and continuousfilaments prepared from blends of two or more polymers and from two ormore polymers present in discrete structural domains in the fiber. Forthe purposes of the invention, the term “polymer” is used in a generalsense, and is intended to include homopolymers, copolymers, graftedcopolymers, and terpolymers. The term blend is also used generallyherein, and is intended to include immiscible and miscible polymerblends. The polymers are considered to be “immiscible” if they exist inseparate, distinct phases in the molten state; all other blends areconsidered to be “miscible.” It is understood that varying levels ofmiscibility can exist, and are also intended to be within the scope ofthis invention.

[0046] Blends with more than two polymers may also be utilized,including those with three or more polymer components. Both immiscibleand miscible polymers may be added to a two component blend to impartadditional properties or benefits with respect to blend compatibility,viscosity, polymer crystallinity or phase domain size.

[0047] Since the polymers employed in the invention will undergoextrusion, stabilizers and antioxidants are conventionally added to thepolymer. Other additives may also be added in accordance with thepresent invention. For example inorganic additives such as titaniumdioxide, talc, fumed silica or carbon black. The polymer resin may alsocontain other additives, such as other polymers, diluents,compatibilizers, antiblocking agents, impact modifiers, plasticizers, UVstabilizers, pigments, delusterants, lubricants, wetting agents,antistatic agents, nucleating agents, rheology modifiers, water andalcohol repellents, and the like. It is also anticipated that additivematerials which have an affect on processing or product properties, suchas extrusion, quenching, drawing, laydown, static and/or electricalproperties, bonding, wetting properties or repellency properties mayalso be used in combination with the blend. In particular, polymericadditives may also be used that impart specific benefits to eitherprocessing and/or end use.

[0048] The multipolymer fibers are normally formed of a polymer blendcomposed of two or more polymers. The polymers of the blend can bemiscible, immiscible, or a combination of miscible and immisciblepolymers. In one embodiment in accordance with the invention, thepolymers may exist as a dominant continuous phase and at least onesubstantially discontinuous dispersed phase. In the case where the blendexists as a dominant continuous phase and at least one discontinuousphase, other polymers may also be present which are either miscible inone, or the other, or both polymer phases.

[0049] According to a further aspect of the invention, the multipolymerfibers are formed of a polymer blend including a relatively low moduluspolymer and at least one higher modulus polymer. It is believed thatthis combination is particularly valuable when the low modulus polymeris the dominant phase and the higher modulus polymer is dispersedtherein. It is theorized that the higher modulus polymer acts toreinforce the low modulus dominant phase, lending stability to spinning,and stiffening the web just enough to allow for higher bond temperatureswhile reducing the risk of the web sticking to and wrapping thecalender. In the case of multipolymer fibers formed of an immisciblepolymer blend it is believed that the small amount of the dispersedpolymer may have the effect of wind up speed suppression (WUSS) on thedominant polymer phase as described by Brody in U.S. Pat. No. 4,518,744.Wind up speed suppression occurs when a small amount of an immiscibleadditive effectively reduces the degree of molecular orientation withinthe fiber at a given filament spinning velocity. The result is afilament with generally higher elongation and lower tenacity.

[0050] In yet another aspect of the invention, the multipolymer fibersare formed of a polymer blend composed of a dominant continuous phase,and at least one polymer, having low mutual affinity with the dominantphase, dispersed therein, and at least one additional polymer which isat least partially miscible in one or the other or both continuous anddispersed polymer phases. If the one additional polymer is miscible inthe dominant phase, and effectively reduces its crystallinity, it isbelieved that the improved extensibility observed in the resultingcomposites may be due to an ‘impact-modifying’ effect. If the oneadditional polymer has an affinity for both polymers, or serves to lowerthe surface energies between the two phases, it is believed that theimprovement observed in the composite extensibility is due to acompatibilization effect. Independent of theory, the blend mustultimately form filaments or fibers, which when formed into webs andcomposite structures exhibit the properties described by the invention,meaning low fuzz and good elongation.

[0051] In one embodiment, the multipolymer fibers may comprise from 1 to50 percent by weight polyethylene and from 99 to 50 percent by weightpolypropylene. Fabrics formed from such blends exhibit low fuzz and goodelongation.

[0052] In applications where tensile strength is particularly importantand high elasticity is of lesser concern, the composite fabric mayinclude a coherent, extensible nonwoven web formed of fibers of apolyethylene and polypropylene blend where the polyethylene is presentin the range of 1% to 10 and the polypropylene is present in the rangeof 90% to 99% by weight. In still another embodiment, very substantialand surprising increases in elongation can be achieved by blending athird polymer component into the blend. For example, the multipolymerfibers may include a dominant amount of a polypropylene, such asisotactic polypropylene, a small amount of a polymer having low mutualaffinity with the dominant polymer, such as polyethylene, and anadditional third polymer which either reduces crystallinity and/orcompatibilizes the blend. What results is a softer web, with extremelyhigh extensibility. Preferred multipolymer fibers according to thisembodiment may comprise greater than 50 percent by weight polypropylene,1 to 10 percent polyethylene, and 10 to 40 percent of the third polymer.Suitable additional third polymers include polypropylene copolymers andterpolymers such as the commercially available Catalloy™ copolymersavailable from Montell. These resins are characterized by having thecomonomer(s) exist to some degree in blocks, and wherein at least someportion of the polymer chain is miscible with one or the other, or both,dominant and dispersed polymer phases. Other suitable polymers are theReflex™ flexible polyolefins from Rexene. These crystallinity reducingresins are characterized as having atactic segments present in thepolymer chain, such that the “tacticity” of the polymer is affected.

[0053] Especially preferred multipolymer fibers according to thisembodiment comprise 65 to 80 percent isotactic polypropylene, 1 to 5percent polyethylene, and 15 to 30 percent of a polyolefin copolymerwherein at least a portion of the chain is miscible with isotacticpolypropylene.

[0054] Another class of useful and advantageous products according tothis aspect of the invention employ multipolymer fibers formed of apolymer blend comprised of a soft, extensible polymer phase, and atleast one additional polymer having low mutual affinity with the soft,extensible phase, such that it modifies either the Theological,mechanical, and/or thermal properties of the fibers in a way thatimproves processability (e.g. melt spinning), bonding and/or abrasionresistance while maintaining high extensibility. In a preferredembodiment the soft, extensible phase is present as a dominant,continuous phase. For example, polyethylene can be used as the soft,extensible dominant phase and a polypropylene as the additionalmodifying polymer. In a preferred embodiment the additional polymer isadded in a small proportion relative to the dominant phase. In anotherpreferred embodiment, the additional polymer exhibits higher viscosityrelative to the dominant phase. Blending a relatively small proportionof the higher viscosity polypropylene with the soft, extensiblepolyethylene imparts greatly increased abrasion resistance to a nonwovenfabric formed from the polymer blend, without significant adverse effectupon other important fabric properties, such as extensibility, softness,tensile strength, etc. The spinnability of the polyethylene is alsoimproved by the presence of the additional polypropylene. According tothis embodiment, the fibers preferably comprise between 2 to 50 percentby weight of the propylene polymer, e.g. 3% ethylene-propylenecopolymer, and 98 to 50 percent by weight of the soft, extensiblepolymer, e.g. polyethylene. In one particularly preferred embodiment,the fiber composition may range from 5 to 40 percent by weight propylenepolymer, and most desirably between 5 to 25 percent by weight propylenepolymer and 75 to 95 percent by weight polyethylene. Especially suitedfor applications requiring good extensibility, tensile strength andabrasion resistance are fiber compositions of from 5 to 25 percent byweight propylene polymer. A most preferred embodiment contains 5 to 25percent by weight of ethylene-propylene copolymer or terpolymer and 75to 95 percent by weight linear low density polyethylene. In theseembodiments, the lower melting polyethylene is present as asubstantially continuous phase in the blend and the higher meltingpropylene polymer is present as a discontinuous phase dispersed in thepolyethylene phase.

[0055] In producing the fibers, the polyethylene and polypropylenecomponents are combined in appropriate proportional amounts andintimately blended before being melt-spun. In some cases sufficientmixing of the polymer components may be achieved in the extruder as thepolymers are converted to the molten state. In other cases, more dynamicmixing may be required.

[0056] Various types of polyethylene may be employed. As an example, abranched (i.e., non-linear) low density polyethylene or a linear lowdensity polyethylene (LLDPE) can be utilized and produced from any ofthe well known processes, including metallocene and Ziegler-Nattacatalyst systems. LLDPE is typically produced by a catalytic solution orfluid bed process under conditions established in the art. The resultingpolymers are characterized by an essentially linear backbone. Density iscontrolled by the level of comonomer incorporated into the otherwiselinear polymer backbone. Various alpha-olefins are typicallycopolymerized with ethylene in producing LLDPE. The alpha-olefins whichpreferably have four to eight carbon atoms, are present in the polymerin an amount up to about 10 percent by weight. The most typicalcomonomers are butene, hexene, 4-methyl-1-pentene, and octene. Ingeneral, LLDPE can be produced such that various density and melt indexproperties are obtained which make the polymer well suited formelt-spinning with polypropylene. In particular, preferred densityvalues range from 0.87 to 0.95 g/cc (ASTM D-792) and melt index valuesusually range from 0.1 to about 150 g/10 min. (ASTM D1238-89, 190° C.).Preferably, the LLDPE should have a melt index of greater than 10, andmore preferably 15 or greater for spunbonded filaments. Particularlypreferred are LLDPE polymers having a density of 0.90 to 0.945 g/cc anda melt index of greater than 25. Examples of suitable commerciallyavailable linear low density polyethylene polymers include thoseavailable from Dow Chemical Company, such as ASPUN Type 6811 (27 MI,density 0.923), Dow LLDPE 2500 (55 MI, 0.923 density), Dow LLDPE Type6808A (36 MI, 0.940 density), and the Exact series of linear low densitypolyethylene polymers from Exxon Chemical Company, such as Exact 2003(31 MI, density 0.921).

[0057] Various polypropylenes made by processes known to the skilledartisan may also be employed. In general, the polypropylene componentcan be an isotactic or syndiotactic propylene homopolymer, copolymer, orterpolymer. Examples of commercially available propylene homopolymerswhich can be used in the present invention include SOLTEX Type 3907 (35MFR, CR grade), HIMONT Grade X10054-12-1 (65 MFR), Exxon Type 3445 (35MFR), Exxon Type 3635 (35 MFR) AMOCO Type 10-7956F (35 MFR), andAristech CP 350 J (melt flow rate approximately 35). Examples ofcommercially available copolymers of propylene include Exxon 9355 whichis a random propylene copolymer with 3% ethylene, 35 melt flow rate;Rexene 13S10A, a 10 melt flow rate random propylene copolymer with 3%ethylene; Fina 7525 MZ, an 11 melt flow rate 3% ethylene randompropylene copolymer, Montel EPIX 30F, a 1.7% ethylene, 8 melt flow raterandom copolymer of propylene. When the propylene polymer is thedominant continuous phase of the blend, the preferred melt flow rate isgreater than 20. When the propylene polymer exists as the dispersedphase of the blend, the preferred melt flow rate is less than 15 andmost preferably less than 10.

[0058] In still another embodiment, the multipolymer fibers of the webmay be bicomponent or multicomponent fibers or filaments. The termbicomponent or multicomponent refers to the existence of the polymerphases in discrete structured domains, as opposed to blends where thedomains tend to be dispersed, random or unstructured. The polymercomponents can be configured into any number of configurations includingsheath-core, side-by-side, segmented pie, islands-in-the-sea, or tippedmultilobal. A coherent extensible nonwoven web can be made, for example,from a sheath-core bicomponent fiber having a polyester core and apolyethylene sheath, or the sheath or core can comprise a blend asdiscussed above. Alternatively, the extensible web can comprise a singleweb containing a combination of spunbonded filament and meltblown fibersor a combination of carded staple fibers and meltblown fibers.

[0059] The extensible nonwoven web, in all embodiments in accordancewith the present invention, is characterized by having high surfaceabrasion resistance and high elongation. The surface abrasion resistanceof the web may be conveniently measured objectively by physical testswhich are standard in the industry, such as the Taber abrasion test asdefined by ASTM Test Method D-3884-80. Extensible webs useful in thecomposite fabrics of the present invention are characterized by having aTaber abrasion value (rubber wheel) of greater than 10 cycles. The websare further characterized by having an elongation at peak load (ASTMD-1682), prior to stretching, in either the machine direction (MD) or inthe cross-machine direction (CD) or both of at least 70 percent, morepreferably at least 100 percent, and most desirably at least 150percent. The multipolymer fibers of the web are of relatively finediameter, typically 10 denier or less.

[0060] The web shown in FIG. 1 has been bonded so that it can bestretched, but has not yet been stretched. The web shown in FIG. 1 hasbeen point bonded by passing the web through a calender nip in which oneof the calender rolls is smooth and one of the calender rolls has apatterned surface for applying the bonding pattern. Intermittent pointbond regions 22 are formed wherein the web is bonded. The discrete bondsites comprise areas where the fibers have been fusion bonded together.It should still be possible to trace an individual filament through thebond site if the bond site is not overbonded. Preferably, the fusedregions cover between 6 and 30 percent of the area of the web, morepreferably 8 to 20 percent, and most preferably 12 to 18 percent of theweb is covered. By bonding the web in accordance with these percentageranges, the filaments are allowed to elongate throughout the full extentof stretching while the strength and integrity of the fabric ismaintained.

[0061] The skilled artisan should recognize that there are myriad otherways to bond a web sufficiently to enable the web to be stretched. Whilethermal point bonding is most preferred for spunbond, carded, and otherwebs, any thermal, chemical, or mechanical bonding treatment may be usedto form a coherent web structure.

[0062] Turning now to a discussion of the properties of the web afterstretching, FIG. 2 represents the nonwoven web 20 of FIG. 1 that hasbeen permanently elongated by mechanical stretching in either themachine direction or the cross direction. It should be understood thatthe web can be subjected to stretching in either of the cross machine ormachine direction to achieve the benefits of the invention, but notboth. Normally, the web is stretched in a direction having an elongationat peak load of at least 70 percent. It should be recognized that thisproperty could be met in one of or both the machine and cross machinedirections.

[0063] The web has been stretched and permanently elongated by thestretching at a temperature of between about 35 to 150 degreesFahrenheit. The web normally is elongated in the absence of heattreatment at an ambient temperature, which typically varies from about65 degrees on a relatively cold day to about 110 degrees on a hot summerday, and most typically is on the order of about 65 to 85 degrees.

[0064] As a result of the “cold” stretching, the nonwoven web developsextraordinary elongation at peak load in the direction perpendicular tothe direction of stretch. Elongation at peak load can be at least about400 to 500% and values above 700% have been achieved. Typically, theratio of elongation at peak load in the direction perpendicular to thedirection of stretch to the elongation at peak load in the stretchdirection is increased at least about 2:1 to more than 10:1. Increase bya factor of at least about 6:1 to 8:1 is typical. Thereafter, the fabricis capable of stretch well beyond the original dimension of the fabricin the direction perpendicular to the stretch direction. The tensilestrength of the webs in the direction of orientation of the filaments,which is normally the stretch direction, is greatly increased. The ratioof tensile strength of the web in the direction of orientation of thefibers to the tensile strength of the web in the other direction is atleast about 10:1 and can be increased to at least about 16:1.

[0065] A further characteristic of the web is high extensibility at lowforce. The nonwoven web has an elongation in one direction, which is thedirection perpendicular to the stretch direction, of at least 70% when aload is applied to the web in that direction that is less than or equalto about 300 grams force per inch. A force of about 300 grams force perinch or less is about the force that the consumer feels on the wristwhen using a fabric in accordance with the invention. The web can beprepared wherein the elongation of the web in the directionperpendicular to the stretch direction is at least 100% to 350% at aload of less than 300 grams force per inch. Table 2, below, showsexamples at 100%, 200%, and 350% elongation at loads of less than 300grams force per inch.

[0066] While not wishing to be bound by theory, it is believed that thefilaments that are not oriented in the stretch direction prior tostretching become oriented in the stretch direction as a result of thestretching, but are either not elongated or are only partiallyelongated. This feature is graphically illustrated in thephotomicrographs shown in FIGS. 10 and 11, which are at 5 and 10×magnification, respectively, and show a multipolymer continuous filamentpointbonded spunbond nonwoven web that has been stretched in the machinedirection. A substantial number of the filaments can be seen to beoriented in the machine direction, which is the direction of stretch. Inany event, the fabric becomes stretchable in the direction perpendicularto the stretch direction to an extent beyond the prestretched dimensionin that direction.

[0067] The fabric also develops a z-direction axis and becomes thickeras the fabric is stretched and the dimension in the directionperpendicular to the stretch direction becomes smaller. The point bonds22, which initially are flat and lie in the plane of the web, becomestrained, and become oriented generally in the z-axis direction withinthe thickness dimension of the fabric and disposed between the opposingfabric surfaces. This detail is graphically illustrated in FIG. 13,which shows in a photomicrograph at 20× magnification the distorted,deformed point bonds of a non-planar configuration embedded in the webbetween opposite surfaces of the web. These bond sites have been pulledinto the body of the spunbond nonwoven web and extend in the Z-directionaxis. Prior to stretching, the pointbond was horizontally oriented asshown in the photomicrograph of FIG. 12, which is also at 20×magnification. Increase in the thickness of the nonwoven web due tostretching can also be seen by comparing FIGS. 12 and 13.

[0068] As shown in FIG. 2, the fabric has been lightly bonded afterstretching with a plurality of point bond sites 24 in a patternreminiscent of cross laid bricks. The point bond sites 24 includefilm-like fused regions that are generally planar and are parallel tothe surface of the web and lie at the web surface. The stretched fabricwas bonded by passing through a calender nip at light pressure and lowheat to stabilize the web and to substantially preclude retraction,since a small about of elastomeric polymer is used in the fibers ofwhich the fabric is made. The bonding is graphically illustrated in thephotomicrographs of FIGS. 10 and 11. It should be recognized that a widevariety of suitable bonding patterns are available and should provideequivalent performance in the practice of the invention. The bondingshould be enough to stabilize the web against retraction of the fibersafter elongation to the desired extent, but not so great as to precludestretching in the direction perpendicular to the stretch direction, forwhich the fabric is designed.

[0069] It is usually advisable to lightly bond the web after stretchingwhen the web will be rolled rather than supplied directly to a laminatorfor lamination with an elastomeric component. The elastomeric componentof the web can cause the web to retract in the roll if the web is notlightly bonded.

[0070] The fabric illustrated in FIG. 2 can be stretched in any ofseveral ways known to the skilled artisan. The fibers normally areextruded, collected on a web forming surface, bonded, and stretched inline. Alternatively, for certain processes, the nonwoven web is rolledprior to stretching and stretching is accomplished as a separateoperation.

[0071] Stretching in the cross machine direction normally isaccomplished using a standard tenter frame.

[0072] It should be recognized that other methods and apparatus can beused to stretch the nonwoven web in the cross direction, although notnecessarily with equivalent results. For example, the web can beincrementally stretched in the cross direction using intermeshing orinterdigitating rollers.

[0073] Typically, the web is stretched in the machine direction. Onemethod of machine direction stretching is schematically represented inFIGS. 3 and 4. It should be recognized that other methods and apparatuscan be used to stretch the nonwoven web in the machine direction,although not necessarily with equivalent results. For example, the webcan be incrementally stretched in the machine direction usingintermeshing or interdigitating rollers.

[0074] As shown in FIG. 3, a nonwoven web of multipolymer fibers 20prepared from the polymer combinations discussed above is supplied froma roll 26 called the unwinder. The web passes around three rolls 28,including a load cell and two idler rolls, arranged at the corners of atriangle for sensing and adjustment of web tension prior to stretchingthe web. The web is stretched by passing through a series of rolls inthree successive S-wrap stations 30, 32, and 34. In each of the S-wrapstations shown, the bottom roller 36, 38, 40 is driven and the toproller and bottom roller form a nip 42, 44, 46 that applies lightpressure to the web that does not bond the web, but provides sufficientgrip that the web can be stretched between the subsequent sets of S-wraprollers. Subsequent S-wrap roll stations are driven at increasing speedsto apply increasing tension to the web between each set of rollers inthe S-wrap station sufficient to stretch the web.

[0075]FIG. 4 represents a partially broken away top perspective view ofa portion of the schematic of FIG. 3 taken along line 4-4. The reductionin the cross direction of the width of the web is shown as the web isstretched in the machine direction, first as the web passes between thefirst and second S-wrap stations 30, 32, and second as the web passesbetween the second and third S-wrap stations 32, 34. The width of theweb is the cross machine direction is considerably reduced between thefirst S-wrap station and the third. The web is permanently elongated.

[0076] It should be recognized that the filaments in the outer portionsof the web tend to be elongated faster than the filaments located in thecenter of the web. For this reason, the distance between the firstS-wrap station and the second should be sufficient to provide that thefilaments in the center of the web are also permanently elongated to thedesired extent.

[0077] It should be recognized that other configurations of rollers canbe used to stretch the web in the machine direction. Rollers can be usedin the omega configuration to apply sufficient tension to the web topermanently elongate the web.

[0078] After stretching, the now permanently elongated web is treated ina manner believed to be known to the skilled artisan to improve itsuniformity by passing over first and second bow rolls 48, 50 to flattenthe web and take out wrinkles. The web is then lightly bonded tostabilize the web against retraction prior to tension adjustment 57 androlling the web on a winder 58 for supply to a line for makingdisposable absorbent articles. The web can be bonded by passing througha calender nip 52 formed between two rollers 54, 56. The calender nipshould be operated at light pressure and low heat.

[0079] The calender preferably is operated so as to take up the web at alower speed than it is supplied by the third S-wrap station 34.Operating the calender at a lower speed than the third S-wrap stationgives the filaments, which have been overstretched to some extent, anopportunity to retract slightly so that they do not retract against thelight bond that is later applied. Alternatively, the lamination linecould be in line, in which case bonding the web may no longer benecessary.

[0080] Table 1 below shows two examples of nonwoven webs prepared inaccordance with the invention and compares these webs with a thenonwoven web prior to stretching. The unstretched web is labelled“Control” in Table 1. The nonwoven control web and the two examples wereall prepared from spunbond continuous filaments prepared from a blend ofa dominant phase of isotactic polypropylene, a dispersed phase of linearlow density polyethylene, and Catalloy™ polymer. TABLE 1 CD MD CDElongation MD Elongation Basis tensile at peak tensile at peak MD/CDMD/CD CD/MD CD/MD Wt. strength load strength load Tensile ElongationTensile Elongation Example g/m² (g/in) (%) (g/in) (%) Ratio Ratio RatioRatio Control Avg.  25.063 908 184.2  2562 191.5   2.82 1.04 0.35  0.96S.D.  0.875  132.5719 25.8    351.4531 15.1  Ex. 1 Avg. 62.07 498.67 750.70  8135.83 70.01 16.32 0.09 0.06 10.72 S.D.  3.22 77.71 98.261250.15 27.02 % Change 148% −45% 308% 218% −63% 478% −91% −83% 1015% Ex.2 Avg. 64.61 517.53  707.35  8512.37 77.25 16.45 0.11 0.06  9.16 S.D. 3.51 69.23 83.60 1075.78 29.67 % Change 158% −43% 284% 232% −60% 483%−89% −83%  852%

[0081] Examples 1 and 2 are were both prepared from the same controlfabric at different line conditions. The relatively slight differencesin the values obtained for the physical characteristics of these webs isdue primarily to differences in line conditions.

[0082] The control fabric had similar physical characteristics in themachine direction as in the cross machine direction, as is reflected bythe ratio of the tensile strength in the machine direction to thetensile strength in the cross direction of 2.82. A value of 2.82 meansthat the nonwoven control web was relatively square in its properties.The balance of properties is also reflected by the MD/CD elongationratio, which reflects that the fabric is stretchable and permanentlyelongatable in either the cross direction or the machine direction.

[0083] Permanent elongation of the control fabric in the machinedirection produced nonwoven webs having the characteristics recited inTable 1 for Examples 1 and 2. The basis weight more than doubled fromabout 25 g/m² to over 60 g/m². The increase in basis weight reflectsthat the dimension of the fabric in the cross direction is greatlyreduce by stretching in the machine direction.

[0084] Tensile strength in the cross direction, CD, in g/in, which isgrams per one inch strip of material, is reduced by nearly half.Elongation at peak load in the cross direction, as a percentage based onthe original width of the web, quadruples, indicating the high degree towhich the web can be stretched in the cross direction, far exceeding thecross machine width of the web prior to stretching. Stretchability inthe cross direction is also reflected by the increase in the ratio ofthe cross direction elongation at peak load to that of the machinedirection of about 10 times.

[0085] Similar, but opposite, values are obtained in the machinedirection. Tensile strength in the machine direction quadruples andelongation at peak load is reduced by about half, indicating that theweb is permanently elongated in the machine direction. The properties ofthe fabric are no longer square.

[0086] Table 2, below, compares the extensibility of the control fabricof Table 1 with that of Example 1, Table 1. The force required to extendthe web is determined at three different elongations. The control fabricrequires a force of 420 grams per inch to elongate the fabric 100%. At200 and 350% elongation, the control web breaks. In contrast, the web ofExample 1 requires a force of only 260 grams per inch to elongate theweb by 350%. TABLE 2 Load at 100% el. Load at 200% el. Load at 350% el.Example (g/in) (g/in) (g/in) Control 420 Breaks Breaks Example 1 52 109260

[0087] A nonwoven web stretched as shown in FIGS. 3 and 4 is illustratedin FIG. 5 in an exploded view of an elastic fabric laminate of theinvention 62. Elastomeric strands 60 are placed between two nonwovenwebs 20 (FIG. 2) and the laminate is bonded, normally by application ofa hot melt or other suitable adhesive. It should be recognized that thelaminate can be prepared with a single nonwoven web on one side toproduce a two layer laminate rather than a three layer laminate, ifdesired. The fabric of the invention has sufficient cover provided by Zaxis development to preclude substantial glue bleed-through. Theelastomeric strands are oriented to stretch in a direction perpendicularto the direction in which the nonwoven webs were permanently elongated.The webs were stretched in the machine direction as shown in FIGS. 3 and4, and so the elastomeric fibers are oriented to stretch in the crossmachine direction.

[0088] The fabric laminate is elastic in the cross machine direction andrecovers substantially all of the distance it is stretched whenstretched below the elastic limit of the elastomeric strands. Thenonwoven webs of the invention can stretch in the cross machinedirection to many times the distance of the initial width of thenonwoven web prior to elongation. Typically, the strands are bonded tothe web directly, without being placed under tension or elongated.

[0089] If it is desired that the fabric laminate stretch in twodirections, then the elastic component that is sandwiched between thenonwoven webs of the invention should provide for stretch in twodirections. The nonwoven web can then be applied to the elasticcomponent so as to form gathers when the elastic component is relaxedthat can allow stretch in the direction in which the web was permanentlyelongated. For example, the web can be applied to tensioned elastomericstrands so that the gathers form when the strands are relaxed. Thelaminate can then be stretched and will exhibit recovery to the extentallowed by the gathers.

[0090] A wide variety of elastic components are suitable for use in thepractice of the invention. Elastomeric strands, scrim, or elastomericfilm, including perforated and nonperforated films and barrier ormoisture vapor transmitting films, are all suitable for use, dependingon the results desired. Elastomeric strands and scrim tend to producefabrics with enhanced breathability as compared to films and arepreferred in countries of high heat and humidity. Films are preferred inmore arid climates since they are cheaper.

[0091] The elastic laminate of the invention is suitable for use as anelastic fabric having highly desirable cloth like characteristics. Thelaminate is suitable for use in a variety of disposable absorbentarticles. The laminate is useful as a stretch side panel in diaperconstruction.

[0092] A disposable diaper 64 is represented in FIG. 6 that incorporatesa pair of elastic side panels 62 made from fabric laminate of theinvention. The diaper is shown in plan view having the outer surfaceback sheet 66 facing the viewer. Internal structure is shown in outlineby the dashed lines. The diaper includes a water pervious topsheet 65(FIG. 7), a water impervious back sheet 66, and an absorbent core 68that typically comprises wood pulp or other absorbent material andtypically includes superabsorbent polymer powder. A surge layer, notshown, may be used to provide a holding area for urine in the frontwaist region for the time required for the superabsorbent polymer totake up the urine after strikethrough.

[0093] The diaper includes front and rear waist bands 70, 72, whichtypically are elasticized. Securing tabs 74 are provided on the backwaist region on opposite sides of the waistband for securing the diaperback waist region to the front waist region about the waist of thewearer. The securing tabs typically are secured to a landing panel onthe front waist region that includes decorative indicia. The tabs can besecured by pressure sensitive adhesive or a hook and loop fasteningsystem similar to Velcro.

[0094] The front and rear waist regions are shown to flare outwardlyfrom the body of the diaper to provide sufficient material to encirclethe waist and to provide for secure attachment of the back waist regionto the front about the waist of the wearer. These outwardly flaredportions are often referred to as ears. The securing tabs extendoutwardly from and are anchored to the ears 76 of the back waist region.

[0095] The elastic side panels of the invention 62 are laminated intothe diaper structure between the back sheet and the topsheet. As shown,the anchored ends of the securing tabs overlap somewhat the elastic sidepanels. The side panels are oriented in the diaper to provide transversestretch, which is in the direction of tension on the securing tab, toimprove the fit of the diaper, even under conditions where the wearer isactive. When made with elastic scrim or elastomeric fibers, thecomposite typically has good breathability, but also contributes tofluid barrier outside the strikethrough and absorbent region. Elasticfilm can also be used as described in Weil et al. U.S. Pat. No.5,242,436, which illustrates a diaper construction having an elasticside panel therein.

[0096] Placement of the elastic side panel of the invention into thediaper is represented in FIG. 7. As shown, the laminate is placedbetween the top sheet and the back sheet so as to provide someelasticity to the ear region in the direction of pull of the securingtab.

[0097] One of the advantages of the invention is that the fabric of theinvention provides a soft, cloth like hand and excellent cover, and yetis exceptionally strong. In the diaper construction illustrated, thetopsheet and the back sheet typically are constructed of inelasticmaterials that do not exhibit stretch and recovery and it normally isnecessary to treat the diaper construction in the region of the elasticside panel so that the topsheet and back sheet will be activated to movewith the elastic side panel. A suitable method for mechanicallyincrementally stretching in the cross direction the composite of the topsheet, elastic stretch laminate of the invention, and the back sheet isdescribed in Weil et al. U.S. Pat. No. 5,242,436.

[0098] The description of the method of U.S. Pat. No. 5,242,436 isincorporated herein by reference in its entirety. The composite passesthrough meshing corrugated rolls as described. Incremental stretching inthe cross direction permanently elongates the topsheet and back sheetcomponents and destroys any light bonding of the elastomeric nonwovenweb composite. The topsheet and the back sheet can now be stretched toprovide for stretching of the elasticized side panel. The fabric of theinvention from which the elasticized side panel is made is sufficientlystrong by virtue of having been already stretched in the machinedirection to withstand the rigors of incremental stretching in thecomposite and to provide a desirable provide cover.

[0099] It should be recognized that the nonwoven fabric laminate of theinvention can be used in the manner described in U.S. Pat. Nos.4,981,747 and 5,114,781 as a fabric that is secured to the securing taband mounted onto the diaper back sheet rather than laminated within thediaper between the topsheet and the back sheet.

[0100] Particular embodiments of the invention have been described indetail in the drawings, photomicrographs, and specification and specificterms have been used. These should be understood in a generic anddescriptive sense and not for purposes of limitation. The scope of theinvention is defined by the claims.

What is claimed is:
 1. A nonwoven web of multipolymer fibers, saidfibers being substantially oriented in one direction, and said webhaving a plurality of discrete bond sites throughout the web bonding thefibers together, and wherein the ratio of the tensile strength of theweb in the direction of orientation of the fibers to the tensilestrength of the web in the other direction is at least about 10:1. 2.The web of claim 1 wherein the ratio of the tensile strength of the webin the direction of orientation of the fibers to the tensile strength ofthe web in the other direction is at least about 16:1.
 3. The web ofclaim 1 wherein the ratio of the elongation at peak load of the web inthe direction transverse to the direction of orientation of the fibersto the elongation at peak load in the direction of elongation is atleast about 6:1.
 4. The web of claim 1 wherein the ratio of theelongation at peak load of the web in the direction transverse to thedirection of orientation of the fibers to the elongation at peak load inthe direction of elongation is at least about 8:1.
 5. The web of claim 1wherein said discrete bond sites comprise areas where the fibers havebeen fusion bonded together.
 6. The web of claim 5 , wherein said bondsites are embedded within the web between opposite surfaces of the weband are of a distorted, non-planar configuration extending generally inthe z-axis direction of the web.
 7. The web of claim 6 additionallyincluding a plurality of bond sites that are generally planar and extendparallel to the surface of the web.
 8. The nonwoven web of claim 1wherein said multipolymer fibers comprise a blend of polypropylene andpolyethylene.
 9. The nonwoven web of claim 1 wherein said multipolymerfibers comprise a blend of two immiscible polymer phases and a thirdcomponent which is at least partially miscible with the two immisciblepolymer phases.
 10. The nonwoven web of claim 1 wherein saidmultipolymer fibers are formed from a blend comprising: a) isotacticpolypropylene present in an amount of from about 65 to 80 percent byweight based upon the weight of said blend; b) linear low densitypolyethylene present in an amount of from about 1 to 5 percent by weightbased upon the weight of said blend; and c) a block or graftedpolyolefin copolymer or terpolymer having at least a portion of thechain thereof miscible with said isotactic polypropylene and whereinsaid block or grafted polyolefin copolymer or terpolymer is present inan amount of from about 15 to 30 percent by weight based upon the weightof said blend.
 11. The nonwoven web of claim 10 wherein themulticomponent fibers are selected from the group consisting of spunbondcontinuous filaments, carded discontinuous staple fibers, and meltblownfibers.
 12. A nonwoven web of multipolymer fibers, said fibers beingsubstantially oriented in one direction, and said multipolymer fiberscomprising a blend of two immiscible polymer phases and a thirdcomponent which is at least partially miscible with the two immisciblepolymer phases, said web having a plurality of discrete point bond sitesthroughout the web bonding the fibers together, said point bond sitescomprising areas where the fibers have been fusion bonded together toform bond sites, said bond sites being of a distorted, non-planarconfiguration extending generally in the z-axis direction of the web.13. A composite fabric comprising at least one layer of an elastomericcomponent bonded to at least one layer comprising the nonwoven web ofclaim 1 or
 12. 14. The composite fabric of claim 13 wherein saidelastomeric component is selected from the group consisting of elasticstrands, elastic film, and scrim comprising elastomeric strands.
 15. Thecomposite fabric of claim 14 wherein said elastic film is breathable.16. A disposable absorbent article comprising as a component thereof,the composite fabric of claim 13 .
 17. A disposable absorbent article ofclaim 16 wherein said composite fabric is a component of an elastic sidepanel for a disposable absorbent garment.
 18. A bonded nonwoven web ofmultipolymer fibers, said nonwoven web having a plurality of discretebond sites throughout the web bonding the fibers together, said bondsites comprising areas where the fibers have been fusion bondedtogether, said bond sites being of a distorted, non-planar configurationextending generally in the z-axis direction of the web, and said webadditionally including a plurality of bond sites that are generallyplanar and extend parallel to the surface of the web.
 19. A bondednonwoven web comprising at least one layer of multipolymer fibers havingan elongation at peak load in one or the other of the machine or crossmachine directions of at least about 400% and a ratio of elongation atpeak load in said one direction to the elongation at peak load in saidother direction of at least about 6:1.
 20. The nonwoven web of claim 19wherein said elongation at peak load is at least about 500%.
 21. Thenonwoven web of claim 19 wherein said ratio of elongation at peak loadin said one direction to the elongation at peak load in said otherdirection is at least about 8:1.
 22. The nonwoven web of claim 19wherein said ratio of elongation at peak load in said one direction tothe elongation at peak load in said other direction is at least about10:1.
 23. The web of claim 19 wherein said web is a cold stretched web.24. A nonwoven web of multipolymer fibers, said web having anextensibility in one direction of at least 70 percent when a load isapplied to the web in said one direction of less than or equal to 300grams force per inch.
 25. The nonwoven web of claim 24 wherein theextensibility of the web in said one direction is at least 100 percent.26. The nonwoven web of claim 24 wherein the extensibility of the web insaid one direction is at least 200 percent.
 27. The nonwoven web ofclaim 24 wherein the extensibility of the web in said one direction isat least 350 percent.
 28. A nonwoven web comprising a plurality ofspunbond continuous filaments formed of a blend of two immisciblepolymer phases and a third component which is at least partiallymiscible with the two immiscible polymer phases, said web having aplurality of discrete point bond sites throughout the web bonding thecontinuous filaments together, said web having an extensibility in onedirection of at least 70 percent when a load of less than or equal to300 grams per inch is applied to said composite fabric in said onedirection.
 29. The composite fabric of claim 28 wherein saidextensibility is at least 100 percent.
 30. The composite fabric of claim28 wherein said extensibility is at least 200 percent.
 31. The compositefabric of claim 28 wherein said extensibility is at least 350 percent.